CRTs among screen display devices for displaying image data on a screen have been widely used. But the CRTs have a large volume and a heavy weight compared to their display area, which have been inconvenient.
Accordingly, thin flat display devices that have a slim profile and a large display area and thus can be easily used in any place have been developed and are gradually replacing CRTs. Particularly, liquid crystal display (LCD) devices have excellent display resolution compared to other flat display device and have fast response time that can be compared to that of CRTs when realizing a moving image.
A driving principle of the LCD device uses optical anisotropy and polarization characteristic of liquid crystal. Liquid crystal has a long and thin structure. Therefore, it is possible to control an alignment direction of liquid crystal molecules by artificially applying an electric field to the liquid crystal molecules having directionality and polarization in the molecular arrangement. Accordingly, when an alignment direction is arbitrarily controlled, light can be transmitted or blocked depending on an alignment direction of the liquid crystal molecules by optical anisotropy of the liquid crystal, so that color and an image can be displayed.
These LCD devices are applied to mobile communication terminals such as portable phones, camera phones, and personal digital assistants (PDAs). In an LCD device applied to a small-sized apparatus such as a mobile communication terminal, a thickness of a substrate constituting an LC panel is formed thin to achieve a slim profile and lightweight of an entire apparatus. For example, a substrate constituting an LC panel can be formed to have a thickness of 0.3-0.5 mm.
FIG. 1 is a schematic plan view of an LCD device according to a related art, FIG. 2 is a cross-sectional view taken along a line A-A′ of FIG. 1, and FIG. 3 is a schematic side view of the LC panel illustrated in FIG. 1.
The related art LCD device includes an LC panel having a first substrate 13 and a second substrate 15, and a mold frame 21. A first polarizer 11 is attached on the first substrate 13, and a second polarizer 17 is attached under the second substrate 15. The first substrate 13 is smaller than the second substrate 15. A driving integrated circuit (IC) 19 for driving the LC panel can be formed on the second substrate 15. The first polarizer 11 and the second polarizer 17 are formed in a similar size smaller than sizes of the first and second substrates 13 and 15. The first polarizer 11 and the second polarizer 17 are formed larger than an image display region of the LC panel.
The first and second substrates 13 and 15, an optical sheet 31, and a light guide plate 33 are coupled to the mold frame 21. The light guide plate 33 and the optical sheet 31 receive light emitted from a light source and provide the received light onto the LC panel.
In an LCD device having the above-described structure, an LC panel may be destroyed by mechanical twisting and impact while an apparatus is treated and carried as the apparatus has an extremely slim profile and lightweight. The arrow illustrated in FIG. 1 indicates impacts are applied to an LCD device from the outside. This external impact is applied to the mold frame 21, and the applied impact is not completely absorbed by the mold frame 21. Therefore, the impact that has not been completely absorbed by the mold frame is delivered to the LC panel.
Meanwhile, the LC panel is separated from a mother substrate through a scribing process and a breaking process during its manufacturing process. At this point, referring to FIG. 4, a fine crack origin is created in a substrate while physical scribing and breaking processes are performed. FIG. 4 is an image illustrating a crack origin is formed in a substrate of a related art LC panel.
The fine crack origin may act as a starting point from which an LCD device starts to be destroyed when twisting and impact are applied to an LC panel. Therefore, it is required that an LCD device applied to a small-sized apparatus of a slim profile and lightweight has impact resistance.